1. Field of the Invention
The invention relates to a transmission chain, suitable for being used between two V-shaped pulleys of a continuously variable transmission, and comprising links which are movably connected relative to one another, as well as means for the power transmission to the pulleys.
2. Description of the Related Art
Such a transmission chain is known from the German Patent Specification 1302795. Said known transmission chain consists of links which are movably connected relative to one another by means of hinge pins. The hinge pins thereby also form, with their end faces, the friction surfaces for the power transmission to the pulleys. In a further embodiment of the known transmission chain, e.g. according to the European Patent Specification 0086038, the dual function of the hinge pins has been overcome in that conical contact elements have been placed around the links, which conical contact elements provide the power transmission with their flanks. In this embodiment the hinge pins only form the hinged connections between the links.
The practical application of the known transmission chain is impeded with, or considerably restricted, by the limited life of the transmission chain and a high sound volume. The life of the chain is largely determined by the weakest part, which is generally formed by the hinge pins. It is true that overdimensioning of the weakest part results in a possibly prolonged life, but it also results in an undesired restriction in the strength/volume-strength/weight ratio and, moreover, leads to an increased sound-volume. The sound-volume which is produced when the transmission chain is being used is especially determined by the sound which is released when the hinge pins or the contact elements collide with the pulleys. Generally a higher-frequency sound is not detected or found to be less annoying than a low-frequency sound. In order to effect a higher-frequency sound when the chain is being used, a limitation of the distance between the hinge pins or the contact elements is aimed at, which results in a larger number of collisions per time unit, with a smaller collision force, and thus in a higher-frequency sound. However, enlarging the weak chain parts in order to prolong the life, on the contrary results in a larger distance between the hinge pins or the friction surfaces, so that it is always necessary to work towards a compromise between life and sound-volume.
The object of the invention is to overcome the drawbacks described, and to provide a transmission chain with an improved life and a reduced sound-volume in comparison with the known transmission chain.